The present invention relates to wind turbines. Particularly, the invention relates to a system for reducing tower vibration and a method of damping tower vibrations. Specifically, the invention relates to a damper system for damping vibrations of a wind turbine, a system for reducing vibrations of a wind turbine and a method for reducing vibrations of a wind turbine.
Wind turbines increase in size and power that is provided by the wind turbine. Thereby, loads and stress on the construction parts, like the tower of the wind turbine, also increases. A compensation of the loads on the tower by providing additional material strength increases the required amount of material and, thus, the costs. Thus, a compensation of the additional loads by stronger and more materials to withstand the loads reduces the competitiveness of wind turbines as compared to other ways of generating energy.
Tower dampers for damping vibrations of the tower may reduce the stress. As a result, the tower can be constructed with a reduced strength and material can be saved to reduce costs. However, the mass required for a passive tower vibration damping is also increasing in the event that the increasing size and output of wind turbines result in increasing loads of the tower.